A new poll shows that while jobs and the economy remain the undisputed top national concerns, almost one-in-five Canadians believe corruption and the Senate are the country's most pressing issues. (CP) | CP

More Canadians said this was of concern than did those who answered that health care, the environment, education, or the debt was most important. This is not particularly good news for Stephen Harper and the Conservatives, who continue to be mired in the Senate scandal that will not go away.

The poll by Nanos confirmed the Tories are still struggling to regain the confidence of voters, with a little less than 30 per cent support. That put them six points behind the Liberals and at their lowest level in Nanos polling since before the 2006 election. The New Democrats were in third with about 25 per cent.

But with jobs and the economy still the top issue for 35 per cent of Canadians, Conservatives are far from sunk — as long as Canadians continue to associate the Tories with a strong economy. There is some indication that they do, with Nanos finding Justin Trudeau ahead of the prime minister on questions of trust and vision, but well behind on competence.

Jobs and the economy jumped 11 points as the top issue of concern since June, boosting the issue to the highest levels it has been since 2009 and the height of the financial crisis. Why Canadians are suddenly so concerned about the economy is not particularly clear, but having voters uncertain about their economic future plays into the hands of incumbent governments everywhere.

The Nanos polling highlights how various issues have waxed and waned in national importance. In the days of Paul Martin, health care was identified as the top issue of national concern despite it being a provincial responsibility. From heights of 30 to 40 per cent, it has sunk to 12 per cent, plummeting especially in the last year. The environment, too, has dropped as an issue to 11 per cent. For a brief time in 2007, when Stéphane Dion and the Liberals came forward with their Green Shift, it was the top issue for roughly one-in-three Canadians.

It is no coincidence that both Trudeau and Thomas Mulcair are trying to beef up their economic credentials, with Liberals emphasizing the middle class and New Democrats moving to the centre on issues related to trade and taxes. Nevertheless, the surprising number of Canadians identifying corruption and the scandals in the Senate as a top concern shows exactly why both parties have an interest in not letting the story die.

But with the Senate hosting a good number of Liberal senators and not a single New Democrat, the advantage would seem to lie with Mulcair. The polls, however, have yet to show anything of the sort.

Éric Grenier taps The Pulse of federal and regional politics for Huffington Post Canada readers every week. Grenier is the author of ThreeHundredEight.com, covering Canadian politics, polls and electoral projections.